Magnetic memory with reduced write current

ABSTRACT

There is provided a magnetic memory including first and second wirings intersecting each other and disposed apart from each other, a magnetoresistance effect film positioned between the first and second wirings, and a first magnetic film including a first portion facing the magnetoresistance effect film with the first wiring interposed therebetween and a pair of second portions positioned on both sides of the first wiring and magnetically connected to the first portion, each of the first and second portions having either one of a high saturation magnetization soft magnetic material containing cobalt and a metal-nonmetal nano-granular film.

This application is a division of application Ser. No. 09/912,321 filedon Jul. 26, 2001, now U.S. Pat. No. 6,556,473.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is based upon and claims the benefit of priority fromthe prior Japanese Patent Applications No. 2000-227320, filed Jul. 27,2000; and No. 2001-157484, filed May 25, 2001, the entire contents ofboth of which are incorporated herein by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a magnetic memory.

2. Description of the Related Art

A magnetoresistance effect device using a magnetic film has already beenused as a magnetic head or a magnetic sensor. Moreover, it is alsoproposed to use the magnetoresistance effect device as a magnetic memory(magnetoresistance effect memory), and the like. In the magnetic memory,a magnetic memory using a ferromagnetic tunnel junction is expected torealize a nonvolatile storage, and a writing or reading access time lessthan 10 nsec, reading and writing endurance exceeding 10¹⁵ times, andsmall cell size like DRAM.

To realize such a magnetic memory using the ferromagnetic tunneljunction, a sufficient magnetoresistance ratio is necessary. In recentyears, the magnetoresistance ratio of 20% or more has been achieved inthe ferromagnetic tunnel junction. Therefore, expectation of realizingsuch a magnetic memory is increased more and more.

For example, a ferromagnetic tunnel junction obtained by forming a thinAl film having a thickness of 0.7 nm to 2.0 nm on a ferromagnetic layer,exposing the surface of the film to an oxygen glow electric discharge oran oxygen gas to form a tunnel barrier layer of Al₂O₃, and furtherforming a ferromagnetic layer has been proposed. According to theferromagnetic tunnel junction, the magnetoresistance ratio of 20% ormore is obtained (J. Appl. Phys. 79, 4724 (1996)). Moreover, a structureof a ferromagnetic single tunnel junction has also been proposed inwhich one layer of a pair of ferromagnetic layers is combined with anantiferromagnetic layer to form a magnetization pinned layer (Jpn. Pat.Appln. KOKAI Publication No. 10-1998).

As described above, in the ferromagnetic single tunnel junction, themagnetoresistance ratio of 20% or more can be obtained. However, ascompared with competing memories such as FeRAM and flash memory, themagnetic memory using the ferromagnetic single tunnel junction has aproblem that power consumption on writing is large.

To solve the problem, a solid magnetic memory has been proposed in whicha thin film of a high permeability material is formed around a writingwiring (U.S. Pat. Nos. 5,659,499, 5,956,267, and 5,940,319, andInternational Patent Application No. WO00/10172). According to thismagnetic memory, since the high permeability film is formed around thewiring, a current value necessary for writing information to a magneticrecording layer can efficiently be reduced. Moreover, according to themagnetic memory, since a magnetic flux generated by the current does notextend to the outside of the high permeable magnetic film, even a crosstalk can be inhibited.

However, in the magnetic memory disclosed in the U.S. Pat. No.5,659,499, a magnetic field cannot uniformly be applied to the wholerecording layer of a magnetoresistance effect film. Moreover, in themagnetic memory disclosed in the U.S. Pat. Nos. 5,956,267 and 5,940,319,when a structure of the magnetic recording layer positioned between apair of magnetization pinned layers like in a dual spin valve typedouble tunnel junction as described later is used, it is difficult toefficiently apply the magnetic field to the magnetic recording layer.Furthermore, the magnetic memory disclosed in the International PatentApplication No. WO00/10172 has an ideal structure for applying themagnetic field to the magnetic recording layer, but it is remarkablydifficult to manufacture the structure.

Moreover, in addition to the aforementioned ferromagnetic single tunneljunction, a ferromagnetic tunnel junction in which a magnetic particleis dispersed in a dielectric material, and a ferromagnetic double tunneljunction (continuous film) have also been proposed. Even in theseferromagnetic tunnel junctions, the magnetoresistance ratio of 20% ormore is obtained (Phys. Rev. B 56(10), R5747 (1997)., Applied MagneticsJournal 23, 4-2 (1999), Appl. Phys. Lett. 73(19), 2829(1998)).Additionally, according to the ferromagnetic double tunnel junction, themagnetoresistance ratio generated by increasing a voltage value appliedto the magnetic tunnel junctions can be prevented from decreasing inorder to obtain a desired signal voltage value.

However, the ferromagnetic double tunnel junction also has a problemthat the power consumption on writing is large similarly as theferromagnetic single tunnel junction. Moreover, when the ferromagneticdouble tunnel junction is used, the magnetic recording layer is heldbetween a pair of tunnel barrier layers and a pair of magnetizationpinned layers. Therefore, even when the method disclosed in theaforementioned U.S. patent is applied, an electric current magneticfield cannot efficiently act on the magnetic recording layer. That is,the magnetic memory using the ferromagnetic double tunnel junction has aproblem that the power consumption on writing is remarkably large.

BRIEF SUMMARY OF THE INVENTION

An object of the present invention is to provide a magnetic memory inwhich a power consumption on writing can be reduced.

According to a first aspect of the present invention, there is provideda magnetic memory comprising first and second wirings intersecting eachother and positioned apart from each other, a magnetoresistance effectfilm positioned between the first and second wirings and comprising amagnetic recording layer configured to reverse a magnetization directionthereof by changing a direction of a magnetic field, which is generatedby passing writing currents through the first and second wirings,between a first direction and a second direction different from thefirst direction, a magnetization pinned layer configured to hold themagnetization direction thereof when the direction of the magnetic fieldis changed between the first direction and the second direction, and anonmagnetic layer intervening between the magnetic recording layer andthe magnetization pinned layer, and a first magnetic film comprising afirst portion facing the magnetoresistance effect film with the firstwiring interposed therebetween and a pair of second portions positionedon both sides of the first wiring and magnetically connected to thefirst portion, each of the first and second portions comprising eitherone of a high saturation magnetization soft magnetic material containingcobalt and a metal-nonmetal nano-granular film.

According to a second aspect of the present invention, there is provideda magnetic memory comprising first and second wirings intersecting eachother and positioned apart from each other, a magnetoresistance effectfilm positioned between the first and second wirings and comprising amagnetic recording layer configured to reverse a magnetization directionthereof by changing a direction of a magnetic field, which is generatedby passing writing currents through the first and second wirings,between a first direction and a second direction different from thefirst direction, first and second magnetization pinned layerssandwiching the magnetic recording layer and each configured to hold amagnetization direction thereof when the direction of the magnetic fieldis changed between the first direction and the second direction, a firstnonmagnetic layer intervening between the first magnetization pinnedlayer and the magnetic recording layer, and a second nonmagnetic layerintervening between the second magnetization pinned layer and themagnetic recording layer, and a first magnetic film comprising a firstportion facing the magnetoresistance effect film with the first wiringinterposed therebetween and a pair of second portions positioned on bothsides of the first wiring and magnetically connected to the firstportion, each of the first and second portions comprising either one ofa high saturation magnetization soft magnetic material containing cobaltand a metal-nonmetal nano-granular film.

According to a third aspect of the present invention, there is provideda magnetic memory comprising first and second wirings intersecting eachother and positioned apart from each other, a magnetoresistance effectfilm positioned between the first and second wirings and comprising amagnetic recording layer configured to reverse a magnetization directionthereof by changing a direction of a magnetic field, which is generatedby passing writing currents through the first and second wirings,between a first direction and a second direction different from thefirst direction, first and second magnetization pinned layerssandwiching the magnetic recording layer and each configured to hold amagnetization direction thereof when the direction of the magnetic fieldis changed between the first direction and the second direction, a firstnonmagnetic layer intervening between the first magnetization pinnedlayer and the magnetic recording layer, and a second nonmagnetic layerintervening between the second magnetization pinned layer and themagnetic recording layer, and a first magnetic film comprising a firstportion facing the magnetoresistance effect film with the first wiringinterposed therebetween and a pair of second portions positioned on bothsides of the first wiring and magnetically connected to the firstportion, the second portions being in contact with one of the first andsecond nonmagnetic layers which is closer to the first magnetic filmthan the other of the first and second nonmagnetic layers.

According to a fourth aspect of the present invention, there is provideda magnetic memory comprising first and second wirings intersecting eachother and positioned apart from each other, a magnetoresistance effectfilm positioned between the first and second wirings and comprising amagnetic recording layer configured to reverse a magnetization directionthereof by changing a direction of a magnetic field, which is generatedby passing writing currents through the first and second wirings,between a first direction and a second direction different from thefirst direction, first and second magnetization pinned layerssandwiching the magnetic recording layer and each configured to hold amagnetization direction thereof when the direction of the magnetic fieldis changed between the first direction and the second direction, a firstnonmagnetic layer intervening between the first magnetization pinnedlayer and the magnetic recording layer, and a second nonmagnetic layerintervening between the second magnetization pinned layer and themagnetic recording layer, and a first magnetic film comprising a firstportion facing the magnetoresistance effect film with the first wiringinterposed therebetween and a pair of second portions positioned on bothsides of the first wiring and magnetically connected to the firstportion, the magnetic recording layer being positioned between thesecond portions.

In the first to fourth aspects of the present invention, when thecurrent is passed through the first wiring, the first magnetic filmprovides a flux path for a generated magnetic force line or magneticflux. Also, the magnetic memory according to first to fourth aspects ofthe present invention may have a ferromagnetic tunnel junction in whichthe nonmagnetic layer is a nonmagnetic tunnel layer (tunnel barrierlayer), or else, may have a so-called giant magnetoresistance (GMR)effect film in which the nonmagnetic layer is not the tunnel barrierlayer.

When the first to fourth aspects of the present invention define aferromagnetic tunnel junction having a structure in which themagnetization pinned layer with the fixed magnetization direction,nonmagnetic tunnel layer, and magnetic recording layer with thereversible magnetization direction are successively laminated, thisferromagnetic tunnel junction includes not only a ferromagnetic singletunnel junction but also a ferromagnetic multiple tunnel junction.Alternatively, when the first to fourth aspects of the present inventiondefine a ferromagnetic tunnel junction having a structure in which thefirst magnetization pinned layer with the fixed magnetization direction,first nonmagnetic tunnel layer, magnetic recording layer with thereversible magnetization direction, second magnetization pinned layerwith the fixed magnetization direction, and second nonmagnetic tunnellayer are successively laminated, this ferromagnetic tunnel junctionincludes a ferromagnetic multiple tunnel junction.

When the magnetoresistance effect film has the first and secondnonmagnetic layers, the first magnetic film can be magneticallyconnected to the magnetic recording layer via either nonmagnetic layer.This can be realized, for example, by employing the following structure.That is, a width of the first nonmagnetic layer and magnetic recordinglayer are set to be larger and the width of the first magnetizationpinned layer is set to be smaller with respect to a distance between thesurfaces of the first and second portions facing to each other. Thereby,the main surface of the first nonmagnetic layer is partially exposed incorrespondence with the first and second portions. In this case, whenthe exposed portions of the first nonmagnetic layer are brought incontact with the first and second portions, the magnetic film ismagnetically connected to the magnetic recording layer via the firstnonmagnetic layer. Therefore, the magnetic flux generated by passing thecurrent through the first wiring and passed through the first magneticfilm can efficiently be applied to the magnetic recording layer. As aresult, information can be written even when an amount of a currentpassed through the first wiring is small, and power consumption requiredfor writing the information can be reduced.

Moreover, when the magnetoresistance effect film has the first andsecond nonmagnetic layers, the magnetic film providing the flux path canalso be magnetically connected to the magnetic recording layer by thefollowing structure. That is, the width of the first magnetizationpinned layer, first nonmagnetic layer and magnetic recording layer isreduced, and set to be not more than the distance between the surfacesof the first and second portions facing to each other. In this case,when the magnetic recording layer is positioned between the first andsecond portions, the magnetic film can be magnetically connected to themagnetic recording layer. Therefore, the information can be written evenwhen the amount of the current passed through the first wiring is small,and the power consumption required for writing the information can bereduced.

In the first to fourth aspects of the present invention, a length of thefirst magnetic film along a longitudinal direction of the first wiringmay be 1.2 times or more, or 1.5 times or more the length of themagnetoresistance effect film along the longitudinal direction of thefirst wiring. Similarly, the length of the second magnetic film alongthe longitudinal direction of the second wiring may be 1.2 times ormore, or 1.5 times or more the length of the magnetoresistance effectfilm along the longitudinal direction of the second wiring. In thiscase, the magnetic field can more effectively be applied to the magneticrecording layer.

The first and second wirings may contain one material selected from thegroup consisting of aluminum, copper, tungsten, and an alloy of thesemetals. Alternatively, the first and second wirings may have amultilayered structure including the nonmagnetic layer and highsaturation magnetization soft magnetic material layer, such as alaminated structure of a Cu layer and CoFeNi layer. When the wirings aremade of the material mainly containing Cu and the first and secondmagnetic films are alloy based films containing Co or Co—Fe as a maincomponent, Cu and Co or Co—Fe are hardly dissolved in each other.Therefore, even when a usual heat treatment process is performed or anexcessively large current is passed, Cu contained in the wiring and Coor Co—Fe contained in the magnetic film are not mutually diffused.Therefore, it is unnecessary to dispose a barrier metal between thewiring and the magnetic film.

Each of the first and second magnetic films can comprise a Co—Fe alloyfilm, a Co—Fe—Ni alloy film, an amorphous material film such as aCo—(Zr, Hf, Nb, Ta, Ti) film, a (Co, Fe, Ni)—(Si, B) based film, a (Co,Fe, Ni)—(P, Al, Mo, Nb, Mn) based film and a (Co, Fe, Ni)—(Si, B)—(P,Al, Mo, Nb, Mn) based film, and metal-nonmetal nano-granular films suchas a (Fe, Co)—(B, Si, Hf, Zr, Sm, Ta, Al)—(F, O, N) based film. In moredetail, these magnetic films may also comprise the high saturationmagnetization soft magnetic material film containing a Co element, orthe metal-nonmetal nano-granular films such as a (Fe, Co)—(B, Si, Hf,Zr, Sm, Ta, Al)—(F, O, N) based film.

It is noted that the metal-nonmetal nano-granular film may have astructure in which metal granules are dispersed in a nonmetal matrix.Alternatively, the metal-nonmetal nano-granular film may have astructure in which nonmetal granules are dispersed in a metal matrix.

The magnetization pinned layer and magnetic recording layer may containFe, Co, Ni, an alloy of these metals, and half metals such as NiMnSb,PtMnSb and Co₂MnGe. A saturation magnetization Bs of the magneticrecording layer may be more than 5 kG.

Moreover, examples of the material of the nonmagnetic tunnel layerinclude Al₂O₃, AlN, MgO, SiO₂, GaO, LaAlO₃, MgF₂, and CaF₂.

In the first to fourth aspects of the present invention, a magnetic filmsimilar to the magnetic film around the first wiring may also beprovided around the second wiring. Moreover, the magnetic film in theposition of the ferromagnetic tunnel junction may also be extended overthe whole wiring.

In the first to fourth aspects of the present invention, with respect toa size in a cross-section vertical to the longitudinal direction of thewiring around which the magnetic film is provided, assuming that thelength of the magnetic film in an opening width direction is 1₁, and thelength thereof in a vertical direction is 1₂, an aspect ratio 1₂/1₁ maybe larger than 1. In this case, the current magnetic field isstrengthened. This aspect ratio 1₂/1₁ may be larger than 1.5 and smallerthan 5, or else, larger than 2 and smaller than 5.

The magnetic memory of the first to fourth aspects of the presentinvention can further comprise a sense current control device configuredto control a sense current passed through the magnetic memory in orderto read the information stored in the magnetic memory. As the sensecurrent control device, a transistor or a diode can be used.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING

FIG. 1A is a sectional view schematically showing a magnetic memoryaccording to a first embodiment of the present invention;

FIG. 1B is a partial sectional view taken along a line 1B—1B of themagnetic memory shown in FIG. 1A;

FIG. 1C is an enlarged sectional view of the structure shown in FIG. 1B;

FIG. 1D is a perspective view schematically showing a part of themagnetic memory shown in FIG. 1A;

FIGS. 2A and 2B are sectional views schematically showing modificationexamples of the structure shown in FIGS. 1A to 1D;

FIG. 3 is a graph showing a relation between a ratio L₂/L₁ of a magneticfilm length L₂ to a magnetoresistance effect film length L₁ and amagnetic field strength H_(x);

FIG. 4 is a circuit diagram showing one example of a circuitconstitution of the magnetic memory according to the first embodiment ofthe present invention;

FIG. 5 is a circuit diagram showing another example of the circuitconstitution of the magnetic memory according to the first embodiment ofthe present invention;

FIG. 6 is a perspective view schematically showing one example of astructure of a magnetic memory in which the circuit constitution shownin FIG. 5 is employed;

FIG. 7A is a sectional view schematically showing the magnetic memoryaccording to a second embodiment of the present invention;

FIG. 7B is a partial sectional view taken along a line 7B—7B of themagnetic memory shown in FIG. 7A;

FIG. 8A is a sectional view schematically showing the magnetic memoryaccording to a third embodiment of the present invention;

FIG. 8B is a partial sectional view taken along a line 8B—8B of themagnetic memory shown in FIG. 8A;

FIG. 9A is a sectional view schematically showing the magnetic memoryaccording to a fourth embodiment of the present invention;

FIG. 9B is a partial sectional view taken along a line 9B—9B of themagnetic memory shown in FIG. 9A;

FIG. 10 is a sectional view schematically showing a part of the magneticmemory according to a fifth embodiment of the present invention;

FIG. 11 is a sectional view schematically showing a part of the magneticmemory according to a sixth embodiment of the present invention;

FIG. 12 is a sectional view schematically showing a part of the magneticmemory according to a seventh embodiment of the present invention;

FIG. 13A is a sectional view schematically showing the magnetic memoryaccording to an eighth embodiment of the present invention;

FIG. 13B is a partial sectional view taken along a line 13B—13B of themagnetic memory shown in FIG. 13A;

FIGS. 14A and 14B are sectional views schematically showing structureexamples of a wiring and magnetic film of the magnetic memory accordingto the eighth embodiment of the present invention;

FIGS. 15A to 15C are sectional views schematically showing structureexamples of the wiring and magnetic film of the magnetic memoryaccording to the eighth embodiment of the present invention; and

FIG. 16 is a sectional view schematically showing a part of the magneticmemory according to a ninth embodiment of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

Embodiments of the present invention will be described in detail belowwith reference to the accompanying drawings. The same reference numeralsdenote the same parts in the drawing, and a duplicate explanation willbe omitted.

FIG. 1A is a sectional view schematically showing a magnetic memoryaccording to a first embodiment of the present invention. FIG. 1B is apartial sectional view taken along a line 1B—1B of the magnetic memoryshown in FIG. 1A, and FIG. 1C is an enlarged sectional view of astructure shown in FIG. 1B. Moreover, FIG. 1D is a perspective viewschematically showing a part of the magnetic memory shown in FIG. 1A.

A magnetic memory 10 shown in FIGS. 1A to 1D is a magnetic random accessmemory (MRAM), and is, as shown in FIG. 1A, mainly constituted by amagnetic memory 11 and a transistor 12 as a sense current control devicefor controlling a sense current to be passed through the magnetic memory11.

The magnetic memory 11 has a ferromagnetic double tunnel junction 13.The ferromagnetic double tunnel junction 13 is positioned betweenwirings 14, 15 crossing at right angles to each other, and a lower endof the tunnel junction is connected to the transistor 12 via a wiring16. Moreover, magnetic films 17, 18 are provided around the wirings 14,15, respectively. Furthermore, in the first embodiment, the magneticfilm 18 is made of a high saturation magnetization soft magneticmaterial. It is noted that a reference numeral 19 denotes an interlayerinsulating film, 20 denotes a substrate, and a double-arrow 26 denotesan axis of easy magnetization.

The ferromagnetic double tunnel junction 13 has a structure in which amagnetization pinned layer 21, tunnel barrier layer 22, magneticrecording layer 23, tunnel barrier layer 24, and magnetization pinnedlayer 25 are laminated in the order noted above from a wiring 16 side. Awidth of the magnetization pinned layer 25 is smaller than that of themagnetization pinned layer 21, tunnel barrier layer 22, magneticrecording layer 23, and tunnel barrier layer 24, and upper surfaces ofthe tunnel barrier layer 24 positioned on opposite sides of the wiring15 are exposed. Both ends of the magnetic film 18 opened on amagnetization pinned layer 25 side contact the exposed upper surfaces ofthe tunnel barrier layer 24, respectively. That is, the magnetic film 18is magnetically connected to the tunnel barrier layer 24, and to themagnetic recording layer 23 via the tunnel barrier layer 24.

When the magnetic film 18 is in contact with the magnetization pinnedlayer 25, the magnetic film 18 is magnetically connected to themagnetization pinned layer 25. Therefore, a current magnetic fieldcannot effectively act on the magnetic recording layer 23. On the otherhand, in the structure shown in FIG. 1C, since the magnetic film 18 isconnected to the magnetic recording layer 23 only via the tunnel barrierlayer 24, the current magnetic field can effectively act on the magneticrecording layer 23.

It is noted that, with this structure, reduction of power consumption toabout ⅕ or less has been confirmed. It is also noted that, a principlefor reducing the power consumption has been described only for themagnetic film 18, but this principle also can be applied to the magneticfilm 17.

Instead of the structure described with reference to FIGS. 1A to 1D,structures shown in FIGS. 2A and 2B may also be employed.

FIGS. 2A and 2B are sectional views schematically showing modificationexamples of the structure shown in FIGS. 1A to 1D.

In the magnetic memory 10 shown in FIG. 2A, the width of themagnetization pinned layer 25 is smaller than an opening width of themagnetic film 18, and the magnetization pinned layer 25 is positionedbetween sidewall portions of the magnetic film 18. In this structure,the current magnetic field can also effectively act on the magneticrecording layer 23.

In the magnetic memory 10 shown in FIG. 2B, the width of themagnetization pinned layer 25 is smaller than the opening width of themagnetic film 18, and the magnetic recording layer 23 is positionedbetween the sidewall portions of the magnetic film 18. In thisstructure, the current magnetic field can also effectively act on themagnetic recording layer 23. Moreover, according to the structure, themagnetic recording layer 23 is positioned between the sidewall portionsof the magnetic film 18. Therefore, when a writing magnetic field isapplied to one of two storage cells adjacent to each other, an influenceof the writing magnetic field onto the magnetic recording layer 23 ofthe other cell is reduced. Therefore, according to the structure shownin FIG. 2B, not only the reduction of the power consumption on writingis achieved but also cross talk can more effectively be prevented.

In the first embodiment, a saturation magnetization Bs of the highsaturation magnetization soft magnetic material for use in the magneticfilms 17, 18 is preferably larger than 5 kG. When the saturationmagnetization Bs is larger than 5 kG, the effect of reducing the powerconsumption conspicuously appears.

Moreover, the length of the magnetic film 17 along the longitudinaldirection of the wiring 14 is preferably more than the length of themagnetoresistance effect film 13 along the longitudinal direction of thewiring 14. This respect will be described with reference to FIG. 3.

FIG. 3 is a graph showing a relation between a ratio L₂/L₁ of a lengthL₂ of the magnetic film 17 along the longitudinal direction of thewiring 14 to a length L₁ of the magnetoresistance effect film 13 alongthe longitudinal direction of the wiring 14, and a magnetic fieldstrength H_(x) in a position of the magnetic recording layer 23. Notethat the graph is obtained by simulation. In FIG. 3, the abscissadenotes the ratio L₂/L₁, and the ordinate denotes the magnetic fieldstrength H_(x).

As shown in FIG. 3, when the ratio L₂/L₁ is larger, a higher magneticfield strength H_(x) is obtained. Moreover, when the ratio L₂/L₁increases to a certain degree, a rise of the magnetic field strengthH_(x) tends to be saturated. In order to more effectively apply themagnetic field to the magnetic recording layer 23, the ratio L₂/L₁ ispreferably 1.2 or more, more preferably 1.5 or more. Similarly, a ratioL₄/L₃ of a length L₄ of the magnetic film 18 along the longitudinaldirection of the wiring 15 to a length L₃ of the magnetoresistanceeffect film 13 along the longitudinal direction of the wiring 15 ispreferably 1.2 or more, more preferably 1.5 or more. In this case, themagnetic field can more effectively be applied to the magnetic recordinglayer 23, and the effect of reducing the power consumption becomes moreconspicuous.

The magnetic film 18 preferably contacts the tunnel barrier layer 24.However, if the magnetic film 18 is magnetically connected to the tunnelbarrier layer 24, and magnetic connection of the magnetic film 18 to themagnetic recording layer 23 is thereby achieved, the magnetic film 18may not contact the tunnel barrier layer 24. Such magnetic connection isrealized when a distance between the magnetic film 18 and the tunnelbarrier layer 24 is 0.1 μm or less, preferably 0.05 μm or less.

Moreover, since a writing time is as short as several nanoseconds (i.e.,the memory is used at a high frequency), a skin depth δ is preferably asub-micron or more. It is noted that the skin depth δ, specificresistance ρ, frequency ω, and permeability μ have a relation asrepresented by the following equation:

δ=(2ρ/ωμ)^(1/2)

Therefore, the specific resistance of the high saturation magnetizationsoft magnetic material is preferably 20 μΩ·cm or more, and morepreferably 50 μΩ·cm or more.

Each of the magnetic films 17, 18 containing the high saturationmagnetization soft magnetic material can be constituted by an alloy filmsuch as a Co—Fe alloy film and a Co—Fe—Ni alloy film; an amorphousmaterial film such as a Co—(Zr, Hf, Nb, Ta, Ti) film and a (Co, Fe,Ni)—(Si, B)—(P, Al, Mo, Nb, Mn) based film; and a metal-nonmetalnano-granular film such as a (Fe, Co)—(B, Si, Hf, Zr, Sm, Ta, Al)—(F, O,N) based film. When these materials are used, and a ratio ofconstituting elements is appropriately adjusted, a magnetostriction canbe set substantially to zero, and the softened magnetic films 17, 18having a small coercive force can be obtained. Note that sectionalshapes of the magnetic films 17, 18 are not limited to those shown inFIGS. 1A to 1D, and various modified shapes can be used.

A cobalt-based alloy containing cobalt as a main component is preferablyused as the high saturation magnetization soft magnetic materialcontained in the magnetic films 17, 18, and a material containing copperas a main component for a high current density is preferably used as thematerial of the wirings 14, 15. In this case, these constitutingmaterials can be prevented from being mutually diffused between thewirings 14, 15 and magnetic films 17, 18. Therefore, a thermal stabilityis enhanced, and a deterioration with an elapse of time can besuppressed.

The magnetization pinned layers 21, 25 may be constituted byferromagnetic layers. The material constituting the ferromagnetic layeris not particularly limited as long as a ferromagnetic property isexhibited. Examples of the material include: metals such as Fe, Co andNi; alloys of these metals; oxides such as a magnetite having a largespin polarization ratio (Fe₃O₄), CrO₂, and RXMnO_(3−y) (R represents arare earth element, and X represents at least one element of Ca, Ba, andSr); and Heusler's alloys such as NiMnSb and PtMnSb. The ferromagneticlayer needs to be thick to such an extent that super-paramagnetism isnot provided, and is preferably 0.4 nm thick or more.

It is preferable to laminate an antiferromagnetic film of Fe—Mn, Pt—Mn,Pt—Cr—Mn, Ni—Mn, Ir—Mn, NiO, and Fe₂O₃ on the ferromagnetic layer, andfix a magnetization direction. Moreover, a laminated film of theferromagnetic and nonmagnetic layers may be used as the magnetizationpinned layers 21, 25. When a three-layer film of a ferromagneticlayer/nonmagnetic layer/ferromagnetic layer is used as the laminatedfilm, it is preferable to generate an antiferromagnetic interactionbetween the ferromagnetic layers via the nonmagnetic layer.

Particularly, in a structure in which an antiferromagnetic film made ofFe—Mn, Pt—Mn, Pt—Cr—Mn, Ni—Mn, Ir—Mn, NiO, and Fe₂O₃ is formed on theferromagnetic film via laminated films such as Co(Co—Fe)/Ru/Co(Co—Fe)and Co(Co—Fe)/Ir/Co(Co—Fe), the magnetization direction of themagnetization pinned layers 21, 25 is hardly influenced by the currentmagnetic field. That is, the magnetization direction of theferromagnetic layer can firmly be fixed.

A ratio L/W of a length L and width W of the magnetic recording layer 23is preferably 1.5 or more, more preferably 2 or more. However, with thestructure shown in FIGS. 1A to 1D, even when the ratio L/W is 1, a highdensity can be realized by a single magnetic domain. Moreover, uniaxialanisotropy is preferably imparted to the magnetic recording layer 23 ina length direction of the layer, and both ends of the layer in thelength direction (a direction of magnetization easy axis) are preferablyconnected to the magnetic film 18 via the tunnel barrier layer 24.

The material for use in the magnetic recording layer 23 is notparticularly limited as long as the ferromagnetic property is exhibited.Examples of the material include: metals such as Fe, Co and Ni; alloysof these metals; oxides such as a magnetite having a large spinpolarization ratio (Fe₃O₄), CrO₂, and RXMnO_(3−y) (R represents a rareearth element, and X represents at least one element of Ca, Ba, and Sr);and Heusler's alloys such as NiMnSb and PtMnSb. The ferromagnetic layerneeds to be thick to such an extent that super-paramagnetism is notprovided, and is preferably 0.4 nm thick or more.

The magnetic recording layer 23 may be of a single layer structure or alaminated structure. When the magnetic recording layer 23 has thelaminated structure, for example, a two-layer film of a softferromagnetic layer/ferromagnetic layer or a three-layer film of aferromagnetic layer/soft ferromagnetic layer/ferromagnetic layer may beused.

Moreover, another structure can also be employed in which the magneticrecording layer 23 is a three-layer film of a ferromagneticlayer/nonmagnetic layer/ferromagnetic layer, and these ferromagneticlayers mutually interact in an antiferromagnetic or weakly ferromagneticmanner via the nonmagnetic layer. In this case, when the currentmagnetic field acts on the magnetic recording layer 23, an influence ofstray field to the magnetization pinned layers 21, 25 from the magneticrecording layer 23 is eliminated. Additionally, even when a memory cellwidth is set to be a sub-micron or less, increase of power consumptionnecessary for generating a predetermined current magnetic field bydiamagnetism can be suppressed. When this structure is employed, it ispreferable that a softer layer is used in the ferromagnetic layer on amagnetic film 18 side, or the film thickness of the layer is set to belarger. Similarly as described above, a two-layer film of a softferromagnetic layer/ferromagnetic layer, or a three-layer film of aferromagnetic layer/soft ferromagnetic layer/ferromagnetic layer can beused as the soft layer.

In addition to the aforementioned magnetic materials, the ferromagneticlayer for use in the magnetization pinned layers 21, 25 and magneticrecording layer 23 can contain nonmagnetic elements such as Ag, Cu, Au,Al, Mg, Si, Bi, Ta, B, C, O, N, Pd, Pt, Zr, Ir, W, Mo, and Nb in a rangein which the ferromagnetic property is not lost. Moreover, theferromagnetic layer for use in the magnetization pinned layers 21, 25preferably has a unidirectional anisotropy parallel to the film surface,and the ferromagnetic layer for use in the magnetic recording layer 23preferably has uniaxial anisotropy parallel to the film surface. Thethickness of the ferromagnetic layer is preferably in a range of 0.1 nmto 100 nm, and is preferably smaller. When the magnetic memory 10 isprepared, the thickness of the ferromagnetic layer is preferably 10 nmor less.

As the material of the tunnel barrier layers 22, 24, dielectricmaterials or insulating materials such as Al₂O₃, AlN, MgO, SiO₂, MgO,LaAlO₃, MgF₂, CaF₂, SrTiO₂, and AlLaO₃ can be used. Omission of oxygen,nitrogen, or fluorine may exist in these materials.

The magnetic memory 10 can be formed on the substrate 20 in a surfaceregion of which at least a part of the transistor 12, and the like areformed. The material of the substrate 20 is not especially limited, andSi, SiO₂, Al₂O₃, spinel, AlN, and the like can be used. Moreover, themagnetic memory 10 is preferably formed on the substrate via aprotective layer or a underlayer. Examples of the material for use inthe protective layer or the underlayer include Ta, Ti, Pt, Pd, Au,Ti/Pt, Ta/Pt, Ti/Pd, Ta/Pd, Cu, Al—Cu, W, and the like.

The magnetic memory 10 can be manufactured using usual thin film formingtechniques such as various sputtering processes, evaporation process,and molecular beam epitaxy process.

A circuit diagram of the aforementioned magnetic memory 10 is shown inFIG. 4.

FIG. 4 is a circuit diagram showing one example of a circuitconstitution of the magnetic memory 10 according to the first embodimentof the present invention. In FIG. 4, the wiring 15 of the magneticmemory 10 shown in FIGS. 1A to 1D is used as a bit line, and the wiring14 is used as a word line. Moreover, in FIG. 4, reference numeral 27denotes a word line, 28 denotes a bit line, 29 denotes a row decoder, 30denotes a column decoder, and 31 denotes a sense amplifier. The magneticmemory 10 shown in FIGS. 1A to 1D can take, for example, this circuitconstitution.

When the magnetic memory 11 shown in FIGS. 1A to 1D is used, themagnetic memory can be realized even with the circuit constitution shownin FIG. 5.

FIG. 5 is a circuit diagram showing another example of the circuitconstitution of the magnetic memory 10 according to the first embodimentof the present invention. Moreover, FIG. 6 is a perspective viewschematically showing one example of the structure of the magneticmemory 11 in which the circuit constitution shown in FIG. 5 is employed.As shown in FIGS. 5 and 6, the ferromagnetic double tunnel junction 13and diode 32 are connected in series with each other, and are connectedto an intersection of the word line 14 and bit line 15. This structurecan also be employed.

A second embodiment of the present invention will next be described.

FIG. 7A is a sectional view schematically showing the magnetic memoryaccording to the second embodiment of the present invention, and FIG. 7Bis a partial sectional view taken along a line 7B—7B of the magneticmemory shown in FIG. 7A. Different from the magnetic memory 10 of thefirst embodiment, in the magnetic memory 10 of the second embodiment,the magnetic films 17, 18 are formed not only in the position of theferromagnetic double tunnel junction 13 but also over the whole wirings14, 15. When this structure is employed, the magnetic films 17, 18 areeasily aligned with the ferromagnetic double tunnel junction 13.

A third embodiment of the present invention will next be described.

FIG. 8A is a sectional view schematically showing the magnetic memoryaccording to the third embodiment of the present invention, and FIG. 8Bis a partial sectional view taken along a line 8B—8B of the magneticmemory shown in FIG. 8A. Different from the magnetic memory 10 of thefirst embodiment, in the magnetic memory 10 according to the thirdembodiment, the magnetic film 17 is disposed not only below but alsoabove the wiring 16. When the structure is employed, the currentmagnetic field from the wiring 14 can more efficiently act on theferromagnetic double tunnel junction 13.

A fourth embodiment of the present invention will next be described.

FIG. 9A is a sectional view schematically showing the magnetic memoryaccording to the fourth embodiment of the present invention, and FIG. 9Bis a partial sectional view taken along a line 9B—9B of the magneticmemory shown in FIG. 9A. In the magnetic memory 10 according to thefourth embodiment, different from the magnetic memory 10 of the firstembodiment, the magnetic films 17, 18 are formed not only in theposition of the magnetic recording layer 23 but also over the wholewirings 14, 15. When the structure is employed, the magnetic films 17,18 can easily be aligned with the ferromagnetic double tunnel junction13. Moreover, in the magnetic memory 10 according to the fourthembodiment, different from the magnetic memory 10 of the firstembodiment, the magnetic film 17 is formed not only below but also abovethe wiring 16. When the structure is employed, the current magneticfield from the wiring 14 can more efficiently act on the ferromagneticdouble tunnel junction 13.

A fifth embodiment of the present invention will next be described.

FIG. 10 is a sectional view schematically showing a part of the magneticmemory according to the fifth embodiment of the present invention. Inthe magnetic memory 10 of the fifth embodiment, different from themagnetic memory 10 according to the first embodiment, the wiring 15 doesnot directly contact the magnetic film 18, and a dielectric film or aninsulating film 19 is positioned between the wiring and the magneticfilm. In this manner, the wiring 15 may electrically contact themagnetic film 18, or may not contact the film.

A sixth embodiment of the present invention will next be described.

FIG. 11 is a sectional view schematically showing a part of the magneticmemory according to the sixth embodiment of the present invention. Inthe magnetic memory 10 according to the first to fifth embodiments, thewiring 15 serving as both the current wiring and the bit line is used.On the other hand, in the magnetic memory 10 according to the sixthembodiment, a current wiring 33 and bit line 34 are providedindependently from each other. When the aforementioned principle isutilized, the current magnetic field can efficiently act on theferromagnetic double tunnel junction 13, and therefore this structure isalso possible.

In the aforementioned first to sixth embodiments, the width of themagnetization pinned layer 25 is set to be smaller than the width of themagnetization pinned layer 21, tunnel barrier layer 22, magneticrecording layer 23, and tunnel barrier layer 24, the upper surfaces ofthe tunnel barrier layer 24 facing the sidewall parts of the magneticfilm 18 are exposed, and the exposed surfaces are utilized tomagnetically connect the magnetic film 18 to the magnetic recordinglayer 23. On the other hand, in the following seventh embodiment, allthe magnetization pinned layer 21, tunnel barrier layer 22, magneticrecording layer 23, tunnel barrier layer 24, and magnetization pinnedlayer 25 are formed to have the same width.

FIG. 12 is a sectional view schematically showing a part of the magneticmemory according to the seventh embodiment of the present invention. Inthe magnetic memory 10 of the seventh embodiment, different from themagnetic memory 10 according to the first embodiment, all themagnetization pinned layer 21, tunnel barrier layer 22, magneticrecording layer 23, tunnel barrier layer 24, and magnetization pinnedlayer 25 are formed to have the same width. Therefore, in a methodsimilar to that of the first to sixth embodiments, the magnetic film 18cannot magnetically be connected to the magnetic recording layer 23.

To solve the problem, in the seventh embodiment, the opening width ofthe magnetic film 18 is set to be not less than the width of theferromagnetic double tunnel junction 13. According to this structure,since the magnetization pinned layer 25 is not disposed between each endof the magnetic film 18 and the magnetic recording layer 23, themagnetic connection of the magnetic film 18 to the magnetic recordinglayer 23 is not inhibited by the magnetization pinned layer 25.Therefore, according to the seventh embodiment, the current magneticfield can efficiently act on the magnetic recording layer, and the powerconsumption required for writing the information can be reduced.

In the seventh embodiment, the distance between the opposite ends of themagnetic film 18 and the magnetic recording layer 23 is not especiallylimited as long as the magnetic connection of the magnetic film 18 tothe magnetic recording layer 23 is achieved, but the closer distance ispreferable. Usually, the distance between the opposite ends of themagnetic film 18 and the magnetic recording layer 23 is sufficiently0.05 μm or less.

An eighth embodiment of the present invention will next be described.

FIG. 13A is a sectional view schematically showing the magnetic memoryaccording to the eighth embodiment of the present invention, and FIG.13B is a partial sectional view taken along a line 13B—13B of themagnetic memory shown in FIG. 13A. The magnetic memory 10 of the eighthembodiment is different from the magnetic memory 10 of the seventhembodiment in that the magnetic film 17 is formed not on a side surfaceof the wiring 14, but only on a bottom surface of the wiring.

When the CMOS transistor 12 is used as a sense current control device,and when the width of the ferromagnetic double tunnel junction 13 (sizein a direction parallel to the bit line 15) is W, and length (size in adirection parallel to the word line. 14) is L, the distance between theadjacent ferromagnetic double tunnel junctions 13 in the longitudinaldirection of the wiring 14 is usually substantially the same as thewidth W. On the other hand, the distance between the ferromagneticdouble tunnel junctions 13 adjacent to each other in the longitudinaldirection of the wiring 15 is substantially three times the width W.That is, in the magnetic memory, the distance between the ferromagneticdouble tunnel junctions 13 adjacent to each other is relatively short inthe width direction, but sufficiently long in the length direction.

Therefore, the cross talk between the ferromagnetic double tunneljunctions 13 adjacent to each other in the longitudinal direction of thewiring 14 needs to be considered, but the cross talk between theferromagnetic double tunnel junctions 13 adjacent to each other in thelongitudinal direction of the wiring 15 does not necessarily have to beconsidered. Therefore, in this case, as shown in FIGS. 13A, 13B, themagnetic film 18 is formed on the side and bottom surfaces of the wiring15, and the magnetic film 17 is not formed on the side surface of thewiring 14 but is formed only on the bottom surface of the wiring. Then,the current magnetic field can efficiently act on the ferromagneticdouble tunnel junction 13 without causing the cross talk.

In the magnetic memory shown in FIGS. 13A and 13B, in order to moreefficiently allow the current magnetic field to act on the ferromagneticdouble tunnel junction 13, structures shown in FIGS. 14A, 14B and FIGS.15A to 15C may be employed.

FIGS. 14A and 14B are sectional views schematically showing a structureexample of the wiring 14 and magnetic film 17 of the magnetic memoryaccording to the eighth embodiment of the present invention. Moreover,FIGS. 15A to 15C are sectional views schematically showing the structureexample of the wiring 15 and magnetic film 18 of the magnetic memoryaccording to the eighth embodiment of the present invention.

In FIG. 14A and FIGS. 15A and 15C, a combination of the wiring 14 andthe magnetic film 17, and a combination of the wiring 15 and themagnetic film 18 constitute two-layer structures. Moreover, in FIG. 14Band FIG. 15B, a combination of the wiring 14 and the magnetic film 17,and a combination of the wiring 15 and the magnetic film 18 constitutethree-layer structures. When the combination of the wiring and themagnetic film constitutes a multiple-layer structure in this manner, ascompared with the single-layer structure, the current magnetic field canmore efficiently act on the ferromagnetic double tunnel junction 13.

In the aforementioned first to eighth embodiments, the reduction of thewriting power consumption by the predetermined structure in the magneticmemory having the ferromagnetic double tunnel junction has beendescribed. In the following ninth embodiment, when the magnetic filmmade of a predetermined material is used, the power consumption duringwriting of the magnetic memory having a ferromagnetic single tunneljunction is reduced.

FIG. 16 is a sectional view schematically showing a part of the magneticmemory according to the ninth embodiment of the present invention. Themagnetic memory 10 of the ninth embodiment has a structure similar tothat of the magnetic memory 10 of the first embodiment. That is, themagnetic memory 10 of the ninth embodiment has a ferromagnetic singletunnel junction 35 in which the magnetization pinned layer 21, tunnelbarrier layer 22, and magnetic recording layer 23 are successivelylaminated. The bit line 34 is formed on the ferromagnetic single tunneljunction 35. The current wiring 33 coated with the magnetic film 18 isformed on the bit line 34 via the insulating film 19. It is noted that,below the ferromagnetic single tunnel junction 35, a wiring is disposedcrossing at right angles to the current wiring 33 and bit line 34, andthe magnetic film is also formed on such wiring.

In the ninth embodiment, the magnetic film 18 is constituted by the highsaturation magnetization soft magnetic material film containing a Coelement or the metal-nonmetal nano-granular film. When this thin film isused, the power consumption necessary for writing the information intothe magnetic recording layer 23 can be reduced.

Examples of the high saturation magnetization soft magnetic materialfilm containing the Co element and constituting the magnetic film 18include: alloy film such as a Co—Fe alloy film and Co—Fe—Ni alloy film;and amorphous material film such as a Co—(Zr, Hf, Nb, Ta, Ti) film and a(Co, Fe, Ni)—(Si, B)—(P, Al, Mo, Nb, Mn) based film. Moreover, examplesof the metal-nonmetal nano-granular film constituting the magnetic film18 include: a (Fe, Co)—(B, Si, Hf, Zr, Sm, Ta, Al)—(F, O, N) basedmetal-nonmetal nano-granular film. When these materials are used, andthe ratio of the constituting elements is appropriately adjusted, themagnetostriction can be set substantially to zero, and the softenedmagnetic film 18 having a small coercive force can be obtained.

In the ninth embodiment, the reduction of the power consumption forwriting the information into the magnetic memory having theferromagnetic single tunnel junction by the magnetic film made of thepredetermined material has been described. However, with the material,the writing power consumption can of course be reduced even in themagnetic memory having the ferromagnetic double tunnel junction.Moreover, in the first to ninth embodiments, the magnetic films areformed on both the pair of wirings intersecting each other via theferromagnetic tunnel junction, but the magnetic film may be formed ononly one of the wirings. In this case, the power consumption on writingcan also be reduced.

Examples of the present invention will be described hereinafter.

EXAMPLE 1

The magnetic memory 10 shown in FIG. 16 was formed in the followingmethod.

First, a Ta underlayer and a 50 nm thick Cu layer were successivelylaminated on an Si/SiO₂ substrate (not shown). Subsequently,successively formed on the Cu layer were a composite film for use as themagnetization pinned layer 21 of a 2 nm thick Ni₈₁Fe₁₉ layer, 12 nmthick Ir₂₂Mn₇₈ layer, and 3 nm thick Co₅₀Fe₅₀ layer; a 1 nm thick Al₂O₃layer for use as the tunnel barrier layer 22; a composite film for useas the magnetic recording layer 23 of a 3 nm thick Co₅₀Fe₅₀ layer and 5nm thick Ta layer; and an Au layer for use as the protective film (notshown).

It is noted that a sputtering process or an evaporation process was usedin forming these thin films, and an initial vacuum degree was 3×10⁻⁸Torr. Moreover, the Al₂O₃ layer was formed by using Al target as asputtering target, and introducing a pure Ar gas as a sputtering gas toform the film in vacuum, and exposing the Al film to plasma oxygen. Inthis method, the thin Al₂O₃ layer was formed without any omission ofoxygen.

Subsequently, the laminated film (including the Au layer to the Ni₈₁Fe₁₉layer on the Cu layer) formed by the aforementioned method was patternedin a size of 4 μm×16 μm using photolithography and ion millingtechniques. The ferromagnetic tunnel junction 35 was formed as describedabove.

Subsequently, while the resist pattern utilized in the patterning wasleft as it was, the 250 nm thick Al₂O₃ layer was formed as theinterlayer insulating film 19 by an electron beam evaporation.Thereafter, the resist pattern was lifted off, and a resist pattern wasfurther formed in order to form the wiring 34. After the surface wascleaned by sputtering, the Cu wiring 34 was formed.

Subsequently, the 250 nm thick interlayer insulating film 19 of SiO₂ wasformed by a reactive sputtering process, and the Au wiring 33 was formedby lifted-off process. Thereafter, the high saturation magnetizationsoft magnetic material was sputtered, the resulting thin film waspatterned in the ion milling process, and the magnetic film 18 wasobtained. As described above, the magnetic memory 10 shown in FIG. 16was formed and thereafter treated in a heat treatment furnace in themagnetic field. As a result, the uniaxial anisotropy was imparted to themagnetic recording layer 23 and the unidirectional anisotropy wasimparted to the magnetization pinned layer 21.

It is noted that a plurality of types of magnetic memories 10 weremanufactured using materials shown in the following table 1 as the highsaturation magnetization soft magnetic material. Moreover, forcomparison, a magnetic memory with no magnetic film 18 formed thereon,and a magnetic memory using a high permeability material Ni—Fe in themagnetic film 18 were also manufactured.

The power consumption of the magnetic memory 10 manufactured in theaforementioned method was measured in the following method. That is,when a current pulse of 10 nsec was passed through the wiring 33, thecurrent magnetic field was exerted onto the magnetic recording layer 23in the easy axis direction 26. Moreover, in a magnetically hard axisdirection, a magnetic field of 20 Oe was exerted using a Helmholtz coil.A current value of current pulse was gradually increased, and a currentIc at which the magnetization of the magnetic recording layer 23 wasreversed was recorded. It is noted that, whether or not themagnetization of the magnetic recording layer 23 was reversed was judgedby passing a direct current through the ferromagnetic single tunneljunction 35 and observing a change of output voltage. Results are alsoshown in the following table 1.

TABLE 1 Material of magnetic film Ic (mA) Co₉₀Fe₁₀ 16 Co₆₀Fe₂₀Ni₂₀ 14Co₃₀Fe₃₀Ni₄₀ 15 Co_(70.3)Fe_(4.7)Si₁₅B₁₀ 13 Co_(75.3)Fe_(4.7)Si₄B₁₆ 13Co_(69.6)Fe_(4.6)Mo_(1.8)Si₈B₁₅ 13 Co₇₀Mn₆B₂₄ 14 Co_(81.5)Mo_(9.5)Zr₉ 15Co₉₆Zr₄ 13 Co₈₇Nb₅Zr₈ 14 Co₈₅Nb_(7.5)Ti_(7.5) 14 Co₉₀Fe₂Nb₈ 13Co₆₀Al₁₀O₃₄ 14 Fe₅₈V₁₃O₂₉ 16 Fe₄₉Al₁₇O₃₄ 16 Fe₄₀B₂₅N₃₅ 15 Fe₅₉Sm₁₇O₂₄ 17absent 45 Ni₈₁Fe₁₉ 22 Ni₆₀Fe₄₀ 20

As shown in the above table 1, in the magnetic memory 10 of the presentexample, as compared with the apparatus having no magnetic film 18, Icis of course low. Even as compared with the use of the high permeabilitymaterial Ni—Fe in the magnetic film 18, a lower Ic was obtained. Thatis, it was confirmed that the writing power consumption was reduced inthe magnetic memory 10 of the present example.

Moreover, a similar test was carried out for the magnetic memory 10having the ferromagnetic double tunnel junction 13. As a result, asimilar tendency was found as described above.

EXAMPLE 2

The magnetic memory 10 shown in FIGS. 1A to 1D was formed in thefollowing method.

First, an SiO₂ film was formed on the Si/SiO₂ substrate using a plasmaCVD process. Subsequently, a damascene process was used to form themagnetic film 17 and wiring 14 on the SiO₂ film.

That is, a stepper was used to form a rectangular recessed portion inthe SiO₂ film. Subsequently, the sidewall and bottom surface of therecessed portion were coated by an Ni₄₀Fe₆₀ film sputtered as the highsaturation magnetization soft magnetic material. Subsequently, therecessed portion was filled with Cu by a plating process. Thereafter,the CMP method was used to remove the high saturation magnetization softmagnetic material film and Cu film positioned outside the recessedportion, and the magnetic film 17 and wiring 14 were formed.

Subsequently, a 250 nm interlayer insulating film of SiO₂ was formed onthe surface of the Si/SiO₂ substrate with the magnetic film 17 andwiring 14 formed thereon by the plasma CVD process. A Ta/W/Ta underlayerand 50 nm thick Cu layer were successively laminated on the interlayerinsulating film (no shown). Subsequently, successively formed on the Culayer were a composite film for use as the magnetization pinned layer 21of a 2 nm thick Ni₈₁Fe₁₉ layer, 12 nm thick Ir₂₂Mn₇₈ layer, and 3 nmthick Co₅₀Fe₅₀ layer; a 1 nm thick Al₂O₃ layer for use as the tunnelbarrier layer 22; a composite film for use as the magnetic recordinglayer 23 of a 2 nm thick Co₅₀Fe₅₀ layer and 5 nm thick Ni₈₁Fe₁₉ layer; a1.2 nm thick Al₂O₃ layer for use as the tunnel barrier layer 24; acomposite film for use as the magnetization pinned layer 25 of a 3 nmthick Co₅₀Fe₅₀ layer, 12 nm thick Ir₂₂Mn₇₈ layer, and 5 nm thick Talayer; and an Au layer for use as the protective film (not shown).

It is noted that the sputtering process or the evaporation process wasused in forming these thin films, and the initial vacuum degree was3×10⁻⁸ Torr. Moreover, the Al₂O₃ layer was formed in a method similar tothat of the Example 1.

Subsequently, the stepper was used to pattern the laminated film(including the Au layer to the Ni₈₁Fe₁₉ layer on the Cu layer) formed inthe aforementioned method in a size of 0.8 μm×4 μm. The ferromagnetictunnel junction 35 was formed in this manner.

Subsequently, a hard mask of SiO₂ and Si₃N₄ able to be mutually etchedwas used to pattern the composite film for use as the magnetizationpinned layer 25 of the Co₅₀Fe₅₀ layer, Ir₂₂Mn₇₈ layer and Ni₈₁Fe₁₉layer, and the Au layer for use as the protective film in a size of 0.8μn×2 μm.

Thereafter, the interlayer insulating film 19 of SiO₂ was formed by theplasma CVD process, the surface of the film was flatted by the CMPprocess, and the upper surface of the Si₃N₄ pattern was exposed. Notethat the thickness of the SiO₂ interlayer insulating film 19 after theCMP process was set to 250 nm. Subsequently, Si₃N₄ pattern was removedby the RIE process, the concave portion was formed, and the Cu wiring 15was formed in the concave portion.

Subsequently, the Si₃N₄ pattern was formed as the hard mask on the SiO₂interlayer insulating film 19, and a trench for the magnetic film 18 wasformed in the SiO₂ interlayer insulating film 19 by the RIE process.Subsequently, a trench structure whose bottom surface was constituted bythe tunnel barrier layer 24 was formed. Subsequently, the Si₃N₄ patternwas removed by the RIE process, and the exposed surfaces wereplasma-oxidized in order to prevent a short circuit between the magneticfilm 18 and the magnetic recording layer 23 and wiring 15. Thereafter, asputtering apparatus having a high directivity was used to sputterNi₄₀Fe₆₀ as the high saturation magnetization soft magnetic material sothat the trench formed in the aforementioned method was filled, theobtained thin film was patterned using the ion milling technique, andthe magnetic film 18 was formed.

As described above, the magnetic memory 10 shown in FIGS. 1A to 1D wasmanufactured, and treated in the magnetic field in the heat treatmentfurnace. Thereby, the uniaxial anisotropy was imparted to the magneticrecording layer 23, and the unidirectional anisotropy was imparted tothe magnetization pinned layers 21, 25.

It is noted that the magnetic memory 10 shown in FIGS. 1A to 1D wasformed in a similar method except that the magnetic film 17 was notformed. It is also noted that, for comparison, a magnetic memory inwhich the structure shown in FIG. 11 was used in the magnetic film 17,ferromagnetic double tunnel junction 13, and magnetic film 18, and amagnetic memory in which the structure shown in FIG. 12 was used in theferromagnetic double tunnel junction 13 and magnetic film 18 withoutforming the magnetic film 17 were prepared. In these comparativemagnetic memories, the distance between the magnetic films 17, 18 andthe magnetic recording layer 23 was set to 0.15 μm.

The power consumption was measured with respect to the respectivemagnetic memories 10 in the following method. That is, a current pulseof 10 nsec was passed through each of the wirings 14, 15, and thecurrent magnetic fields were exerted onto the magnetic recording layer23 in a direction of the magnetization easy axis 26 and in a directionof the magnetization hard axis. It is noted that the current value ofthe current pulse passed through the wiring 14 was set to 5 mA. It isalso noted that the current value of the current pulse passed throughthe wiring 15 was gradually increased, and the current Ic at which themagnetization of the magnetic recording layer 23 was reversed wasrecorded. Additionally, whether or not the magnetization of the magneticrecording layer 23 was reversed was judged by writing the information,passing the direct current through the ferromagnetic double tunneljunction 13 and observing the output voltage change. Results are shownin the following table 2.

TABLE 2 Structure of magnetic storage device Magnetic film 17 Ic (mA)FIGS. 1A-1D Present  3.5 FIGS. 1A-1D Absent   5.1 FIG. 12 Present 17.5FIG. 12 Absent 19  

As shown in the above table 2, it was confirmed that in the magneticmemory 10 of the present example having the trench structure (with thestructure shown in FIGS. 1A to 1D), as compared with the magnetic memory10 having no trench structure (having the structure shown in FIG. 12)and having a long distance between the magnetic films 17, 18 and themagnetic recording layer 23, Ic was low, and the power consumption forwriting was reduced. Moreover, it was confirmed that in the magneticmemory 10 including the magnetic film 17 and having an increasingmagnetic field to be exerted in the magnetically hard axis direction, ascompared with the magnetic memory 10 including no magnetic film 17, Icof the magnetically easy axis direction 26 was small, and the powerconsumption for writing was further reduced.

EXAMPLE 3

The magnetic memory 10 shown in FIGS. 1A to 1D was prepared in a methodsimilar to the method of Example 2 except that the ferromagnetic doubletunnel junction 13 was constituted as shown in the following tables 3and 4 and the materials shown in the following tables 3 and 4 were usedin the magnetic films 17, 18. The power consumption was measured withrespect to the magnetic memory 10 prepared as described above in asimilar method except that the current value of the current pulse passedthrough the wiring 14 was set to 3 mA. Results are also shown in thetables 3 and 4.

TABLE 3 Structure of ferromagnetic double tunnel junction Material ofmagnetic film Ic (mA) PtMn/Co₉Fe/AlN/Fe₅₅Co₄₅/AlN/ Co₉₀Fe₁₀ 2.5Co₈FeNi/PtMn Co_(70.3)Fe_(4.7)Si₁₅B₁₀ 2.1 (17 nm/3 nm/2 nm/5 nm/2.6 nm/Co₉₀Fe₂Nb₈ 2.2 3 nm/19 nm) Ir₂₂Mn₇₈/CoFe/Al₂O₃/Fe₁₀Co₉₀/ Co₃₀Fe₃₀Ni₄₀2   Al₂O₃/CoFe/Ir₂₂Mn₇₈ Co_(69.6)Fe_(4.6)Mo_(1.8)Si₈B₁ 1.9 (15 nm/3nm/1.2 nm/3 nm/1.4 nm/ Co₆₀Al₁₀O₃₄ 2.1 5 nm/20 nm)NiMn/CoFe/SiO₂/CoFe/Ni₈₁Fe₁₉/ Co₉₀Fe₁₀ 2   CoFe/SiO₂/CoFe/NiMnCo_(69.6)Fe_(4.6)Mo_(1.8)Si₈B₁ 2   (19 nm/3 nm/1.8 nm/2 nm/4 nm/Fe₄₉Al₁₇O₃₄ 2.1 2 nm/2 nm/5 nm/20 nm) Ir₂₂Mn₇₈/CoFeNi/Al₂O₃/FeCo₂Ni/Co₆₀Fe₂₀Ni₂₀ 2.4 Al₂O₃/CoFeNi/Ir₂₂Mn₇₈ Co_(70.3)Fe_(4.7)Si₁₅B₁₀ 2.2 (15nm/2 nm/1.0 nm/5 nm/1.2 nm/ Co₈₅Nb_(7.5)Ti_(7.5) 2.1 3 nm/17 nm)Ir₂₂Mn₇₈/CoFeNi/Al₂O₃/FeCo/ Co₉₀Fe₁₀ 2   Ni₈₁Fe₁₉/FeCo/Al₂O₃/CoFeNi/Co_(75.3)Fe_(4.7)Si₄B₁₆ 1.9 Ir₂₂Mn₇₈ Co₉₀Fe₂Nb₈ 1.9 (15 nm/2 nm/1.0 nm/3nm/5 nm/ 3 nm/1.2 nm/3 nm/17 nm) Ir₂₂Mn₇₈/CoFe/Al₂O₃/FeCo/Ru/Co₆₀Fe₂₀Ni₂₀ 1.8 Fe₃Co₇/Al₂O₃/CoFe/Ir₂₂Mn₇₈ Co₉₆Zr₄ 1.7 (15 nm/2 nm/1.0nm/3 nm/0.7 nm/ Fe₄₀B₂₅N₃₅ 1.7 5 nm/1.2 nm/3 nm/17 nm)

TABLE 4 Structure of ferromagnetic double tunnel junction Material ofmagnetic film Ic (mA) Ir₂₂Mn₇₈/CoFe/Ir/FeCo/Al₂O₃/FeCo/ Co₉₀Fe₁₀ 1.6Ir/Fe₃Co₇/Al₂O₃/CoFe/Ir/FeCo/ Co_(70.3)Fe_(4.7)Si₁₅B₁₀ 1.5 Ir₂₂Mn₇₈Co₈₅Nb_(7.5)Ti_(7.5) 1.5 (15 nm/2 nm/0.8 nm/3 nm/1.0 nm/ 3 nm/0.8 nm/3nm/1.2 nm/3 nm/ 0.8 nm/3 nm/17 nm) Ir₂₂Mn₇₈/CoFe/Ru/FeCo/Al₂O₃/Co₃₀Fe₃₀Ni₄₀ 1.7 Fe₉Co/Ru/Fe₉Co/Al₂O₃/CoFe/Ru/Co_(69.6)Fe_(4.6)Mo_(1.8)Si₈B₁₅ 1.5 FeCo/Ir₂₂Mn₇₈ Fe₄₉Al₁₇O₃₄ 1.9 (15nm/2 nm/0.7 nm/3 nm/1.0 nm/ 3 nm/0.7 nm/5 nm/1.2 nm/3 nm/ 0.7 nm/3 nm/17nm) Ir₂₂Mn₇₈/CoFe/Ru/FeCo/Al₂O₃/ Co₃₀Fe₃₀Ni₄₀ 1.8FeCo/Ni₈Fe₂/CoFe/Ru/FeCo/Ni₈Fe₂/ Co₇₀Mn₆B₂₄ 1.6CoFe/Al₂O₃/CoFe/Ru/FeCo/Ir₂₂Mn₇₈ Co₆₀Al₁₀O₃₄ 1.7 (12 nm/2 nm/0.7 nm/2nm/1.0 nm/ 2 nm/2 nm/2 nm/0.7 nm/2 nm/4 nm/ 2 nm/1.2 nm/3 nm/0.7 nm/3nm/ 12 nm) PtMn/CoFe/Ru/FeCo/Al₂O₃/FeCo/ Co₉₀Fe₁₀ 1.4Ni₈Fe₂/CoFe/Ru/FeCo/Ni₈Fe₂/CoFe/ Co_(75.3)Fe_(4.7)Si₄B₁₆ 1.3Al₂O₃/CoFe/Ru/FeCo/PtMn Fe₄₀B₂₅N₃₅ 1.4 (15 nm/2 nm/0.7 nm/2 nm/1.0 nm/ 2nm/2 nm/2 nm/0.7 nm/2 nm/5 nm/ 2 nm/1.2 nm/3 nm/0.7 nm/3 nm/ 17 nm)Ir₂₂Mn₇₈/CoFe/Ru/FeCo/Al₂O₃/ Co₆₀Fe₂₀Ni₂₀ 1.4FeCo/Ni₄Fe₆/CoFe/Ru/FeCo/Ni₄Fe₆/ Co₉₆Zr₄ 1.3CoFe/Al₂O₃/CoFe/Ru/FeCo/Ir₂₂Mn₇₈ Co₈₅Nb_(7.5)Ti_(7.5) 1.2 (15 nm/2nm/0.7 nm/2 nm/1.0 nm/ 2 nm/3 nm/2 nm/2 nm/0.7 nm/2 nm/ 4 nm/2 nm/1.2nm/3 nm/0.7 nm/ 3 nm/17 nm)

As shown in the above Tables 3 and 4, Ic was sufficiently low in anycase, but when the magnetic films 17, 18 were constituted by the highsaturation magnetization soft magnetic material film containing the Coelement and metal-nonmetal nano-granular film, Ic was especially low,and it has also been seen that the writing power consumption was furtherreduced. Moreover, it has also been seen that when the three-layer filmof the ferromagnetic layer/nonmagnetic layer/ferromagnetic layer wasused, and an antiferromagnetic interaction was exerted between theferromagnetic layers via the nonmagnetic layer, Ic did not increase, andthe power consumption was further reduced.

As described above, in the present invention, since the magnetic film ismade of the predetermined material, the power consumption necessary forwriting the information into the magnetic memory can be reduced.Moreover, since the magnetic film is used and the predeterminedstructure is employed in the present invention, the power consumptionnecessary for writing the information can also be reduced even in themagnetic memory having the ferromagnetic double tunnel junction.

That is, according to the present invention, there is provided amagnetic memory in which power consumption on writing is reduced.

Additional advantages and modifications will readily occur to thoseskilled in the art. Therefore, the invention in its broader aspects isnot limited to the specific details and representative embodiments shownand described herein. Accordingly, various modifications may be madewithout departing from the spirit or scope of the general inventiveconcept as defined by the appended claims and their equivalents.

What is claimed is:
 1. A magnetic memory comprising: first and secondwirings intersecting each other and positioned apart from each other; amagnetoresistance effect film positioned between the first and secondwirings and comprising, a magnetic recording layer configured to reversea magnetization direction thereof by changing a direction of a magneticfield, which is generated by passing writing currents through the firstand second wirings, between a first direction and a second directiondifferent from the first direction, a first magnetization pinned layerpositioned between the first wiring and the magnetic recording layer andconfigured to hold a magnetization direction thereof when the directionof the magnetic field is changed between the first direction and thesecond direction, and a first nonmagnetic layer intervening between themagnetic recording layer and the first magnetization-pinned layer; and afirst magnetic film with a U-shaped cross-section covering one mainsurface of the magnetoresistance effect film with the first wiringinterposed therebetween and covering side surfaces of themagnetoresistance effect film with an insulating film interposedtherebetween.
 2. The memory according to claim 1, wherein the firstmagnetic film also covers side surfaces of the first magnetizationpinned layer with the insulating film interposed therebetween.
 3. Thememory according to claim 1, wherein the first magnetic film furthercovers side surfaces of the magnetic recording layer with the insulatingfilm interposed therebetween.
 4. The memory according to claim 1,wherein the magnetoresistance effect film further comprises, a secondmagnetization pinned layer configured to hold a magnetization directionthereof when the direction of the magnetic field is changed between thefirst direction and the second direction, the first and the secondmagnetization pinned layers sandwiching the magnetic recording layer andthe first nonmagnetic layer, and a second nonmagnetic layer interveningbetween the magnetic recording layer and the second magnetization pinnedlayer.
 5. The memory according to claim 1, further comprising a secondmagnetic film with a U-shaped cross-section covering the other mainsurface of the magnetoresistance effect film with the second wiringinterposed therebetween and covering side surfaces of the second wiring.6. The memory according to claim 1, wherein a length of the firstmagnetic film along a longitudinal direction of the first wiring is 1.2times or more a length of the magnetoresistance effect film along thelongitudinal directional of the first wiring.
 7. The memory according toclaim 1, wherein the first magnetic film comprises either a highsaturation magnetization soft magnetic material containing cobalt or ametal-nonmetal nano-granular film.
 8. The memory according to claim 7,wherein the first magnetic film comprises a high permeability magneticmaterial as the high saturation magnetization soft magnetic material,the high permeability magnetic material is an alloy containing cobalt orcobalt-iron as a main component, and the first and second wiringscontain one-material selected from the group consisting of copper,tungsten, and an alloy of copper and tungsten.
 9. The memory accordingto claim 7, wherein the first magnetic film comprises a highpermeability magnetic material as the high saturation magnetization softmagnetic material, the high permeability magnetic material is an alloycontaining cobalt or cobalt-iron as a main component, and each of thefirst and second wirings has a multilayered structure including anonmagnetic layer and a high saturation magnetization soft magneticmaterial layer.
 10. The memory according to claim 7, wherein the firstmagnetic film comprises at least one film selected from the groupconsisting of a Co—Fe alloy film, a Co—Fe—Ni alloy film, a Co—(Zr, Hf,Nb, Ta, Ti) film, an amorphous film of these films, and a metal-nonmetalnano-granular film.
 11. The memory according to claim 1, wherein thenonmagnetic layer is a nonmagnetic tunnel layer.
 12. The memoryaccording to claim 1, further comprising a sense current control elementconfigured to control a sense current to be passed through the magneticmemory.
 13. A magnetic memory comprising: first and second wiringsintersecting each other and positioned apart from each other; amagnetoresistance effect film positioned between the first and secondwirings and comprising, a magnetic recording layer configured to reversea magnetization direction thereof by changing a direction of a magneticfield, which is generated by passing writing currents through the firstand second wirings, between a first direction and a second directiondifferent from the first direction, a first magnetization pinned layerpositioned between the first wiring and the magnetic recording layer andconfigured to hold a magnetization direction thereof when the directionof the magnetic field is changed between the first direction and thesecond direction, the first magnetization pinned layer being narrowerthan the magnetic recording layer, and a first nonmagnetic layerintervening between the magnetic recording layer and the firstmagnetization pinned layer, the first nonmagnetic layer being wider thanthe first magnetization pinned layer; and a first magnetic film with aU-shaped cross-section covering one main surface of the firstmagnetization pinned layer with the first wiring interposed therebetweenand covering side surfaces of the first magnetization pinned layer withan insulating film interposed therebetween, both ends of the firstmagnetic film being in contact with a surface of the first nonmagneticlayer on the side of the first magnetization pinned layer.
 14. Thememory according to claim 13, wherein the magnetoresistance effect filmfurther comprises, a second magnetization pinned layer configured tohold a magnetization direction thereof when the direction of themagnetic field is changed between the first direction and the seconddirection, the first and the second magnetization pinned layerssandwiching the magnetic recording layer and the first nonmagneticlayer, and a second nonmagnetic layer intervening between the magneticrecording layer and the second magnetization pinned layer.
 15. Thememory according to claim 13, further comprising a second magnetic filmwith a U-shaped cross-section covering one main surface of themagnetoresistance effect film with the second wiring interposedtherebetween and covering side surfaces of the second wiring.
 16. Thememory according to claim 13, wherein a length of the first magneticfilm along a longitudinal direction of the first wiring is 1.2 times ormore a length of the magnetoresistance effect film along thelongitudinal directional of the first wiring.
 17. The memory accordingto claim 13, wherein the first magnetic film comprises a high saturationmagnetization soft magnetic material containing cobalt or ametal-nonmetal nano-granular film.
 18. The memory according to claim 17,wherein the first magnetic film comprises a high permeability magneticmaterial as the high saturation magnetization soft magnetic material,the high permeability magnetic material is an alloy containing cobalt orcobalt-iron as a main component, and the first and second wiringscontain one material selected from the group consisting of copper,tungsten, and an alloy of copper and tungsten.
 19. The memory accordingto claim 17, wherein the first magnetic film comprises a highpermeability magnetic material as the high saturation magnetization softmagnetic material, the high permeability magnetic material is an alloycontaining cobalt or cobalt-iron as a main component, and each of thefirst and second wirings has a multilayered structure including anonmagnetic layer and a high saturation magnetization soft magneticmaterial layer.
 20. The memory according to claim 17, wherein the firstmagnetic film comprises at least one film selected from the groupconsisting of a Co—Fe alloy film, a Co—Fe—Ni alloy film, a Co—(Zr, Hf,Nb, Ta, Ti) film, an amorphous film of these films, and a metal-nonmetalnano-granular film.
 21. The memory according to claim 13, wherein thenonmagnetic layer is a nonmagnetic tunnel layer.
 22. The memoryaccording to claim 13, further comprising a sense current controlelement configured to control a sense current to be passed through themagnetic memory.
 23. A magnetic memory comprising: first and secondwirings intersecting each other and positioned apart from each other; amagnetoresistance effect film positioned between the first and secondwirings and comprising, a magnetic recording layer configured to reversea magnetization direction thereof by changing a direction of a magneticfield, which is generated by passing writing currents through the firstand second wirings, between a first direction and a second directiondifferent from the first direction, a first magnetization pinned layerfacing the magnetic recording layer and configured to hold amagnetization direction thereof when the direction of the magnetic fieldis changed between the first direction and the second direction, and afirst nonmagnetic layer intervening between the magnetic recording layerand the first magnetization-pinned layer; and a first magnetic film witha U-shaped cross-section covering one main surface of the first wiring,which is opposite to the other main surface of the first wiring thatfaces the magnetoresistance effect film, and covering side surfaces ofthe first wiring the magnetoresistance effect film being sandwichedbetween portions of the first magnetic film that covers the sidesurfaces of the first wiring with an insulating film interposedtherebetween.
 24. The memory according to claim 23, wherein themagnetoresistance effect film further comprises, a second magnetizationpinned layer configured to hold a magnetization direction thereof whenthe direction of the magnetic field is changed between the firstdirection and the second direction, the first and the secondmagnetization pinned layers sandwiching the magnetic recording layer andthe first nonmagnetic layer, and a second nonmagnetic layer interveningbetween the magnetic recording layer and the second magnetization pinnedlayer.
 25. The memory according to claim 23, further comprising a secondmagnetic film with a U-shaped cross-section covering one main surface ofthe second wiring, which is opposite to the other main surface of thesecond wiring that faces the magnetoresistance effect film, and coveringside surfaces of the second wiring.
 26. The memory according to claim23, wherein a length of the first magnetic film along a longitudinaldirection of the first wiring is 1.2 times or more a length of themagnetoresistance effect film along the longitudinal directional of thefirst wiring.
 27. The memory according to claim 23, wherein the firstmagnetic film comprises either a high saturation magnetization softmagnetic material containing cobalt or a metal-nonmetal nano-granularfilm.
 28. The memory according to claim 27, wherein the first magneticfilm comprises a high permeability magnetic material as the highsaturation magnetization soft magnetic material, the high permeabilitymagnetic material is an alloy containing cobalt or cobalt-iron as a maincomponent, and the first and second wirings contain one materialselected from the group consisting of copper, tungsten, and an alloycopper and tungsten.
 29. The memory according to claim 27, wherein thefirst magnetic film comprises a high permeability magnetic material asthe high saturation magnetization soft magnetic material, the highpermeability magnetic material is an alloy containing cobalt orcobalt-iron as a main component, and each of the first and secondwirings has a multilayered structure including a nonmagnetic layer and ahigh saturation magnetization soft magnetic material layer.
 30. Thememory according to claim 27, wherein the first magnetic film comprisesat least one film selected from the group consisting of a Co—Fe alloyfilm, a Co—Fe—Ni alloy film, a Co—(Zr, Hf, Nb, Ta, Ti) film, anamorphous film of these films, and a metal-nonmetal nano-granular film.31. The memory according to claim 23, wherein the nonmagnetic layer is anonmagnetic tunnel layer.
 32. The memory according to claim 23, furthercomprising a sense current control element configured to control a sensecurrent to be passed through the magnetic memory.
 33. A magnetic memorycomprising: first and second wirings intersecting each other andpositioned apart from each other; a magnetoresistance effect filmpositioned between the first and second wirings and comprising, amagnetic recording layer configured to reverse a magnetization directionthereof by changing a direction of a magnetic field, which is generatedby passing writing currents through the first and second wirings,between a first direction and a second direction different from thefirst direction, a first magnetization pinned layer facing the magneticrecording layer and configured to hold a magnetization direction thereofwhen the direction of the magnetic field is changed between the firstdirection and the second direction, and a first nonmagnetic layerintervening between the magnetic recording layer and the firstmagnetization-pinned layer; and a first magnetic film with a U-shapedcross-section covering one main surface of the first wiring, which isopposite to the other main surface of the first wiring that faces themagnetoresistance effect film, and covering side surfaces of the firstwiring the magnetic recording layer being sandwiched between portions ofthe first magnetic film that covers the side surfaces of the firstwiring with an insulating film interposed therebetween.
 34. The memoryaccording to claim 33, wherein the magnetoresistance effect film furthercomprises, a second magnetization pinned layer configured to hold amagnetization direction thereof when the direction of the magnetic fieldis changed between the first direction and the second direction, thefirst and the second magnetization pinned layers sandwiching themagnetic recording layer and the first nonmagnetic layer, and a secondnonmagnetic layer intervening between the magnetic recording layer andthe second magnetization pinned layer.
 35. The memory according to claim33, further comprising a second magnetic film with a U-shapedcross-section covering one main surface of the second wiring, which isopposite to the other main surface of the second wiring that faces themagnetoresistance effect film, and covering side surfaces of the secondwiring.
 36. The memory according to claim 33, wherein a length of thefirst magnetic film along a longitudinal direction of the first wiringis 1.2 times or more a length of the magnetoresistance effect film alongthe longitudinal directional of the first wiring.
 37. The memoryaccording to claim 33, wherein the first magnetic film comprises eithera high saturation magnetization soft magnetic material containing cobaltor a metal-nonmetal nano-granular film.
 38. The memory according toclaim 37, wherein the first magnetic film comprises a high permeabilitymagnetic material as the high saturation magnetization soft magneticmaterial, the high permeability magnetic material is an alloy containingcobalt or cobalt-iron as a main component, and the first and secondwirings contain one material selected from the group consisting ofcopper, tungsten, and an alloy of copper and tungsten.
 39. The memoryaccording to claim 37, wherein the first magnetic film comprises a highpermeability magnetic material as the high saturation magnetization softmagnetic material, the high permeability magnetic material is an alloycontaining cobalt or cobalt-iron as a main component, and each of thefirst and second wirings has a multilayered structure including anonmagnetic layer and a high saturation magnetization soft magneticmaterial layer.
 40. The memory according to claim 37, wherein the firstmagnetic film comprises at least one film selected from the groupconsisting of a Co—Fe alloy film, a Co—Fe—Ni alloy film, a Co—(Zr, Hf,Nb, Ta, Ti) film, an amorphous film of these films, and a metal-nonmetalnano-granular film.
 41. The memory according to claim 33, wherein thenonmagnetic layer is a nonmagnetic tunnel layer.
 42. The memoryaccording to claim 33, further comprising a sense current controlelement configured to control a sense current to be passed through themagnetic memory.